Illius augustus timmis and edgar william timmis



PATENTED JAN. 19, 1904.

I. A. & E. W. TIMMIS.

BLEGTROMAGNET.

APPLICATION FILED JUNE 19, 1903.

H0 MODEL.

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UNITED STATES Patented January 19, 1904.

PATENT OFFICE.

ILLIUS AUGUSTUS TIIWIMIS AND EDGAR WILLIAM TIMMIS, OF LONDON,

' ENGLAND.

ELECTROMAGNET.

SPECIFICATION forming part of Letters Patent No. 750,132, dated January19, 1904.

Application filed June 19, 1903. Serial No. 162,374. (Ni model.)

To a whom, it may concern.-

Be it known that we, ILLIUs AUGUSTUS TIM- M18 and EDGAR WILLIAM TIMMIs,subjects of the King of Great Britain, residing at London, in the countyof Middlesex, England, have invented new and useful Improvements inElectromagnets, of which the following isaspecification.

Our invention has relation to electromagnets, and has for its object theprovision of means whereby the range and power of an electromagnet maybe increased without a corresponding increase in the quantity of wirewith which the magnet is wrapped or in the electric current by which themagnet is energized.

In Letters Patent of the United States granted to Illius A. TimmisOctober 10, 1893, No. 506,282, an electromagnet is shown and describedin which a helix is lined and partly covered with magnetizable metal andhas an armature provided with a core that enters the helix and adepending lip that when the core is nearly home in the helix comes downover the uncovered part of the latter. In this electromagnet the wire ofthe helix, its hollow core and covering, and the core and depending lipof the armature have parallel sides.

In carrying our present invention into effeet we make the helix oftapering form exteriorly and interiorly, either or both, and the coreand depending lip of the armature of corresponding form, so that as thearmature is attracted its surfaces adjacent to the surfaces of the helixwill gradually approach the latter until in contact therewith. By thisconstruction we give to the magnet greater.

power and longer range of motion than has been attained in magnets ofthe ordinary construction.

Our invention consists in the novel eonstruetions, combinations, andarrangements of parts hereinafter described and claimed.

Referring to the accompanying drawings, Figure 1 is a vertical sectionalview of an electromagnet constructed according to our invention, andFigs. 2, 3, 4, and 5 similar views of modified forms of the same.

H designates the helix, which is composed of suitably-insulated wire andis mounted on a bottom plate B of magnetizable material.

A designates the armature, which is formed with a tapering core O and atapering depending lip or rim R. The interior and exterior surfaces ofthe helix are tapered on lines parallel with the adjacent surfaces ofthe core and rim of the armature, and while the parallelism of theadjacent surfaces of the helix and core is maintained throughout theentire range of motion of the armature these surfaces will constantlyapproach one another or draw closer together during the entire range ofmotion of the armature toward the helix.

In the simplest form of our improvement (illustrated in Fig. l of thedrawings) the helix H is composed solely of insulated wire coiled in theform shownthat is, with its outer surface tapering inwardly from bottomto top and the cavity in its center tapering inwardly from top tobottom. The core O of the armature is tapered on lines parallel with thetaper of the cavity of the helix, and the depending rim or lip R istapered on lines parallel with the exterior surface of the same.

In Fig. 2 of the drawings we have shown a modified form of ourimprovement in which the helix H is cylindrical, but is provided with alining t of magnetizable material and a covering L of like material, thelining and covering being in magnetic contact with the bottom plate Band both being tapered toward the top, as shown, so that the surfaces ofthe helix in this form of our improvement are the same as in the helixshown in Fig. 1. In the magnet shown in Fig. 2 we have shown an armaturehaving a core and a depending lip of considerably greater length thanthe correspondingparts of the magnet shown in Fig. 1, the range ofmotion of the armature shown in Fig. 2 being, however, the same as thatof the armature of Fig. 1.

In Fig. 3 we have shown another modifica tion, in which the lining t andthe covering 6 of the helix are made up of separate rings of magneticmaterial and do not extend quite up to the top of the helix, the coilsof the helix above the lining and covering being formed so as tocontinue the tapering lines of the two. These rings may be joined toeach other and to the plate B.

In Fig. 1 we have shown a construction similar to that shown in Fig. 3,except that the lining and covering are each a single piece instead ofbeing formed of separate rings.

In still another modification (shown in Fig. 5) the lower half of thehelix is formed of magnetizable metal which is grooved on top, so as toextend part way on the interior and exterior of the coiled wire H.

If desired, the bottom plate B in any of the forms shown may extendbeyond the outer surface of the helix and in under its central cavity,as shown in dotted lines in Fig. 1, so that the core C and rim R whenhome may rest on and adhere to the bottom plate. A top I), ofnon-magnetizable material, may be fitted to the helix, and in some casesin order to reduce or eliminate the effect of eddy-currents we slot thearmature-rim, as shown at E E in Fig. 1.

If desired, the angle of bevel given to the surfaces of the helix andarmature core and rim can be arranged at so slight a degree fromparallel lines that the magnet can be arranged to work as a solenoid,with the enormous advantage that there is a holding pull at the maximumof force exercised or at any prearranged point of travel.

By means of the constructions above described we are able to obtain along stroke with a strong pull; but it is sometimes advisable, and oftenimperative, to keep the force that is exercised at the commencement ofthe movement of the armature the same all through that movement. Toeffect this, the magnetizable-metal core and rim, either or both, may beextended through and beyond the bobbin, as shown in the dotted lines inFig. 2, so as to set up a counter attractive force, and thus neutralizethe excessive attractive force, or the magnetizable parts of thearmature which enter or come within the attraction of the helix arebeveled off or the parts of the helix which are farthest away from thearmature at the commencement of the stroke are cut away or formed sothat as the parts of the armature enter or are drawn over the outside ofthe helix there is an increasing air-gap, as shown at G, Fig. 1.

At any part or parts in either the armature or helix we may fit such asubstance as parafiin or cannel-coal or an equivalent substance havingthe power of hindering the electric (or active magnetic) lines of forceto control the pulling or attractive force between the bobbin or helixand the armature.

Having described our invention, we claim- 1. In an electromagnet, thecombination with a helix having a tapering central cavity and a taperingexternal surface, of a naked armature having a tapering core and atapering rim, substantially as described.

2. The combination in an electron'iagnet of a helix having a taperingcentral cavity and a tapering external surface with a naked armaturehaving a core and a depending rim both tapered on lines parallel to theadjacent surfaces of the helix, substantially as described.

3. The combination in an electromagnet, of a helix having a lining andcovering of mag netizable material, the said lining and covering beingof increasing thickness from top to bottom, substantially as described,with a naked armature having a tapering core and a tapering rim, as setforth.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

ILLIUS AUGUSTUS 'llllVIMlS. EDGAR WILLIAM TIMMIS.

\Vitnesses:

WV ALTER E. Rooms, ARTHUR NIBLOOK.

